With the recent increase in the importance of energy storage and conversion technology, various kinds of electrochemical devices are receiving attentions, and among them, secondary batteries are being mainly studied.
However, in case a metal electrode (for example, a lithium metal electrode, a sodium metal electrode, etc.) is used as an anode of the secondary battery, irreversible decomposition reactions may occur at the interface contacting solvents, metal salts, impurities, etc. in electrolyte, and the reaction products may be formed as a solid electrolyte interphase (SEI) on the surface of the metal electrode.
Such a solid electrolyte interphase is continuously formed with repeated decomposition and generation according to repeated charge/discharge, and causes performance deterioration of secondary batteries such as resistance increase on the surface of a metal electrode, and the resulting energy efficiency decrease, etc.
And, partial current density difference is induced by the solid electrolyte interphase, and it becomes a cause of dendrite formation on the surface of a metal electrode during charge. Such dendrite gradually grows by repeated charge/discharge, and causes internal short circuit between a cathode and an anode, thus causing performance deterioration of secondary batteries such as stability deterioration of secondary batteries, decrease in battery capacity, shortening of life characteristic, etc.